311312220 has 48 divisors (see below), whose sum is σ = 879838848. Its totient is φ = 82239040.

The previous prime is 311312203. The next prime is 311312227. The reversal of 311312220 is 22213113.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 311312220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311312227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17826 + ... + 30665.

It is an arithmetic number, because the mean of its divisors is an integer number (18329976).

Almost surely, 2^311312220 is an apocalyptic number.

311312220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

311312220 is an abundant number, since it is smaller than the sum of its proper divisors (568526628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

311312220 is a wasteful number, since it uses less digits than its factorization.

311312220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48610 (or 48608 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 311312220 is about 17644.0420539059. The cubic root of 311312220 is about 677.7435442910.

Adding to 311312220 its reverse (22213113), we get a palindrome (333525333).

The spelling of 311312220 in words is "three hundred eleven million, three hundred twelve thousand, two hundred twenty".